The present invention relates to a building and construction material consisting substantially of binding agents such as cement, and mineral filler materials, a method of producing the building and construction material and a method of reducing the degree of shrinkage in the building and construction material.
The present invention is a further development of European Patent Application EP 0 647 603 which is equivalent to U.S. Pat. No. 5,641,815 and in which a construction and building material, such as concrete is disclosed which includes uniformly dispersed micropores. These superfine pores have a diameter in the range of about 0.01.mu. to about 5.mu., whereby the individual pores are themselves closed.
In this way, it is possible to build structures and building parts with a substantial higher strength in comparison with common concrete. The pores include an amount of air which is conventionally included in concrete for anti-freezing effect but the concrete is stronger than conventional concrete.
The micropores are obtained by mixing the binding agent or reactive material, such as cement, with additives, such as tensides and water in a conventional mixer or in a high turbulence mixer, in order to be thereafter or directly mixed in one processing step in a conventional concrete mixer with the aggregate such as sand and gravel. In case no additives are used, a high turbulence mixer must be used. In case additives such as tensides are used, the mixing of the cement with water can proceed in a conventional mixer.
The inclusion of micropores finds specific application for the production of so called lightweight building materials, such as those containing lightweight filler materials, in that due to the increase of the strength of the concrete enclosing the filler materials, the finally resulting lightweight building material has a sufficient strength.